在NHEJ中对DNA-PKcs结构中间体的冷EM可视化
Siyu Chen1,2, Alex Vogt1,2, Linda Lee3
1Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
Science advances
|May 31, 2023
概括
通过非同类末端连接 (NHEJ) 来修复DNA双链断裂 (DSB). 这项研究揭示了DNA-PKcs如何通过构造变化调节NHEJ复杂过渡,暴露DNA断裂进行修复.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- DNA双链断裂 (DSB) 是高度细胞毒性的DNA病变.
- 非同类末端连接 (NHEJ) 途径通过一系列调节的蛋白质复合体过渡来修复DSB.
- 核心NHEJ因子最初形成一个长距离 (LR) 突触复合体,该复合体在DNA末端对齐时过渡到短距离状态.
研究的目的:
- 为了可视化和描述NHEJ复合体的关键过渡状态.
- 在NHEJ期间阐明DNA-PKcs的作用和结构动态.
- 为了揭示DNA-PKcs在DSB修复中的调节周期.
主要方法:
- 单粒子冷电子显微镜 (冷电子显微镜).
- 多个NHEJ复合体的结构分析.
- 研究DNA-PKcs形状和自酸化效应.
主要成果:
- 另外三个NHEJ过渡状态被冷EM可视化.
- 在整个NHEJ过程中,DNA-PKcs采用了不同的二维形状.
- DNA-PKcs的自酸化诱导LR复合体的结构变化,促进DNA断裂暴露和解离.
结论:
- 在NHEJ期间,DNA-PKcs经历了显著的结构变化.
- 这些动态变化对于调节DNA断裂暴露和处理至关重要.
- 在NHEJ中提出了DNA-PKcs调节周期的综合模型.
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